It has stirred vigorous and predictable debate about what causes the "wage gap" by which the average female employee is said to earn approximately 80 cents for every dollar paid to a man.

But what I view as Farrell's most controversial point remains undiscussed. Namely, should women use affirmative action -- that is, government-mandated preferences -- to 'correct'the free market's wage gap and make more money? Farrell, who is usually associated with male empowerment, says "yes."

He provides detailed advice on how to do so, for example through tax-funded tuition and other programs unavailable to men.

The first part of the book revolves around refuting feminism's explanation of the wage gap: namely that it results from rampant discrimination against women in the workplace.

Many arguments surrounding the wage gap are not addressed, however.

For example, women's lack of access to various well-paying blue collar jobs due to union policies and attitudes. But addressing such arguments is not the book's purpose. Refuting the specific feminist claim of discrimination is. And Farrell ably accomplishes this goal on two levels.

First, he cites research and extensive government data to demonstrate that women who compete for the same job often earn more than men, not less.

In Table 6, Farrell compares the starting salaries for women and men with Bachelor's Degrees in 26 categories of employment, from investment banker to dietician. Women are paid equally in one category; in every other category, their starting salaries exceed men's. A female investment banker's starting salary is 116 percent of a man's. A female dietician's is 130 percent; that is, $23,160 compared to $17,680.

Second, Farrell analyzes the data that does reflect a wage gap. But rather than seeing oppression in the data, he perceives free choice.

He argues: women commonly prefer jobs with shorter and more flexible hours to accommodate the demands of family. Compared to men, they generally favor jobs that involve little danger, no travel and good social skills. Such jobs generally pay less.

Farrell rejects the conclusion of 'discrimination'because it does not reflect the fact that female employees express different preferences than males.

Men's rights advocate Carey Roberts identifies one such difference. "[T]he sheer amount of work. According to the Bureau of Labor Statistics, full-time men clock an average of 45 hours a week, while women put in 42 hours. Men are more than twice as likely as women to work at least 50 hours a week."

Women's lifestyle choices partly explain their absence from certain professions, especially dangerous ones. Roberts observes, "Men represent 92 percent of all occupational deaths. Why? Because if you look at a list of the most hazardous occupations -- fire fighting, truck driving, construction, and mining -- they have 96-98 percent male employees, according to the Bureau of Labor Statistics."

Farrell believes that women can make the same salaries as men and enter "male professions" if they are willing to make the same employment choices. Accordingly, he offers practical advice to women, much of which is extremely useful.

Nevertheless, I balk whenever Farrell offers advice on how to maximize government privileges at the expense of men, who must compete at a disadvantage and pay taxes for programs that exclude them from benefits.

For example, under the heading "Get Hazard Pay Without the Hazards," Farrell tells women to enter dangerous occupations. There they can reap the same salary as men while avoiding comparable risk because employers who are compelled to hire women commonly shield them from risks.

Thus, Farrell explains, women get a "'death professions bonus'with not much more physical risk than in everyday life."

Using the military as an example, Farrell argues that women "comprise approximately 15 percent of active-duty military personnel, and 10 percent of those deployed in Iraq." Yet women constitute approximately 2.6 percent of soldiers killed in Iraq; men constitute 97.4 percent. Indeed, "in the Marines and Air Force it's a 100 percent chance of returning." That's because a daughter is "much more likely to choose, or be chosen for, the military's safer fields."

Farrell offers an explanation as to why women's safety becomes a priority. "Whether…on an Alaskan fishing boat or in the American military, men's protective instinct toward women, and women's protective instinct toward themselves (and children) keeps men more disposable than women."

In short, men will assume greater risk to protect a woman co-worker. Farrell calls this male protective instinct "touching."

(Of course, many women don't wish to be "shielded" from the job they signed on to do. Others find it offensive for policies to assume women can't or shouldn't work on an equal footing beside men. Such women do not wish to exploit those policies; they want to change them.)

But quite another factor underlies the situations that continue to make men "more disposable": government policy. Indeed, even private industry commonly implements preference for women's safety out of fear of lawsuits for harms such as exposure to chemicals or other stress during pregnancy.

A government that discriminates on the basis of sex or race violates a basic principle of justice. The law must apply to every human being equally.

This is the core of my disagreement: Farrell believes in affirmative action and, so, advises women to 'game the system'in order to make money. I reject affirmative action and, so, seek to eliminate the system in order to make justice.

Nevertheless, Why Men Earn More goes on my reference shelf as a book I will quote and re-read despite disagreements.

Wendy McElroy is the editor of ifeminists.com and a research fellow for The Independent Institute in Oakland, Calif. She is the author and editor of many books and articles, including the new book, "Liberty for Women: Freedom and Feminism in the 21st Century" (Ivan R. Dee/Independent Institute, 2002). She lives with her husband in Canada.